Source code for airflow.triggers.external_task

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from __future__ import annotations

import asyncio
import datetime
import typing

from asgiref.sync import sync_to_async
from sqlalchemy import func
from sqlalchemy.orm import Session

from airflow.models import DagRun, TaskInstance
from airflow.triggers.base import BaseTrigger, TriggerEvent
from airflow.utils.session import NEW_SESSION, provide_session


[docs]class TaskStateTrigger(BaseTrigger): """ Waits asynchronously for a task in a different DAG to complete for a specific logical date. :param dag_id: The dag_id that contains the task you want to wait for :param task_id: The task_id that contains the task you want to wait for. If ``None`` (default value) the sensor waits for the DAG :param states: allowed states, default is ``['success']`` :param execution_dates: :param poll_interval: The time interval in seconds to check the state. The default value is 5 sec. """ def __init__( self, dag_id: str, task_id: str, states: list[str], execution_dates: list[datetime.datetime], poll_interval: float = 5.0, ): super().__init__() self.dag_id = dag_id self.task_id = task_id self.states = states self.execution_dates = execution_dates self.poll_interval = poll_interval
[docs] def serialize(self) -> tuple[str, dict[str, typing.Any]]: """Serializes TaskStateTrigger arguments and classpath.""" return ( "airflow.triggers.external_task.TaskStateTrigger", { "dag_id": self.dag_id, "task_id": self.task_id, "states": self.states, "execution_dates": self.execution_dates, "poll_interval": self.poll_interval,
}, )
[docs] async def run(self) -> typing.AsyncIterator["TriggerEvent"]: """ Checks periodically in the database to see if the task exists, and has hit one of the states yet, or not. """ while True: # mypy confuses typing here num_tasks = await self.count_tasks() # type: ignore[call-arg] if num_tasks == len(self.execution_dates): yield TriggerEvent(True) await asyncio.sleep(self.poll_interval)
@sync_to_async @provide_session
[docs] def count_tasks(self, *, session: Session = NEW_SESSION) -> int | None: """Count how many task instances in the database match our criteria.""" count = ( session.query(func.count("*")) # .count() is inefficient .filter( TaskInstance.dag_id == self.dag_id, TaskInstance.task_id == self.task_id, TaskInstance.state.in_(self.states), TaskInstance.execution_date.in_(self.execution_dates), ) .scalar() ) return typing.cast(int, count)
[docs]class DagStateTrigger(BaseTrigger): """ Waits asynchronously for a DAG to complete for a specific logical date. :param dag_id: The dag_id that contains the task you want to wait for :param states: allowed states, default is ``['success']`` :param execution_dates: The logical date at which DAG run. :param poll_interval: The time interval in seconds to check the state. The default value is 5.0 sec. """ def __init__( self, dag_id: str, states: list[str], execution_dates: list[datetime.datetime], poll_interval: float = 5.0, ): super().__init__() self.dag_id = dag_id self.states = states self.execution_dates = execution_dates self.poll_interval = poll_interval
[docs] def serialize(self) -> tuple[str, dict[str, typing.Any]]: """Serializes DagStateTrigger arguments and classpath.""" return ( "airflow.triggers.external_task.DagStateTrigger", { "dag_id": self.dag_id, "states": self.states, "execution_dates": self.execution_dates, "poll_interval": self.poll_interval,
}, )
[docs] async def run(self) -> typing.AsyncIterator["TriggerEvent"]: """ Checks periodically in the database to see if the dag run exists, and has hit one of the states yet, or not. """ while True: # mypy confuses typing here num_dags = await self.count_dags() # type: ignore[call-arg] if num_dags == len(self.execution_dates): yield TriggerEvent(self.serialize()) await asyncio.sleep(self.poll_interval)
@sync_to_async @provide_session
[docs] def count_dags(self, *, session: Session = NEW_SESSION) -> int | None: """Count how many dag runs in the database match our criteria.""" count = ( session.query(func.count("*")) # .count() is inefficient .filter( DagRun.dag_id == self.dag_id, DagRun.state.in_(self.states), DagRun.execution_date.in_(self.execution_dates), ) .scalar() ) return typing.cast(int, count)

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